Prediction of Young’s modulus of single wall carbon nanotubes by molecular-mechanics based finite element modelling

The aim of this paper is to propose a Single Walled Carbon Nanotube (SWCNT) finite element (FE) model, based on the use of non-linear and torsional spring elements, to evaluate its mechanical properties. The choice of the spring elements to build the FE model, was based on the observation that other elements as beam, truss or shell are not very applicable because of the complex interaction of many atoms and the absence of rotational degrees of freedom. Moreover, it was also possible to model the bond interaction without introducing any non-physical variable, such as area and inertia of atoms linkage when using beam elements. With the proposed model, the influence of tube diameter and chirality on the Young’s modulus of SWCNTs was investigated. In particular, armchair, zig-zag and chiral nanotubes, with different size, were tested under uniaxial load. The results show that good agreement was achieved with existing experimental results. The presented results demonstrate that the proposed FE model may also provide a valuable numerical tool for the prediction of the strength behaviour of single walled carbon nanotubes.